In nowadays, when purchasing consumer products, consumers not only consider the functionalities but also gradually pay attention to the product appearances, such that processing molding methods of appearance elements of the consumer products become diversified and important. Accordingly, applications and demands for performing processing procedures, such as cutting, welding, drilling, mold micro-machining and so forth, on a non-plane object or a workpiece become more widespread.
A processing machine performs a positioning process by using a laser light source to project on the workpiece, and enables the processing equipment to perform a processing procedure according to positioning point. If a processing surface is a curved or a non-plane surface, the pros and cons of the processing effect will be directly influenced by a relationship between a focal-point position of the laser light source and a tilt angle on the processing surface. If an operator desires to perform an automated processing procedure on workpieces of the same type by the processing machine, there are few differences of a distance and an angle between each workpiece and each processing equipment (e.g. an automated robot arm), which leads to errors occurring in each operation. Further, even though the processing machine would dutifully perform the processing procedure according to the data inputted by the operator, the stereoscopic workpieces still have their own tolerances, and as a result, the errors occur.
Accordingly, manufacturers would like an apparatus capable of detecting relations between laser light spots and the tilt angles on the workpiece surfaces to be installed on the processing machine, such that the processing machine may perform the processing procedures on the workpieces more accurately. Currently, devices for determining the tilt angle on the workpiece may be implemented by various manners. A first manner is to project a laser light source on a workpiece and monitor a distance and a tilt angle between the workpiece and the processing machine according to the reflection of the laser light source. However, such reflective measurement is limited by the roughness and reflectivity of the processing surface and requires a more tilting angle for the laser light to reflect. Additionally, the reflective measurement is incapable of simultaneously measuring tilt angles of two dimensions, and therefore, more time-consuming. A second manner is to detect the distance between the processing equipment and the workpiece by using a sensing capacitor; however, such capacitive measurement is influenced by environmental factors (e.g. degrees of a temperature and humidity) and thus, requires a compensating process and is difficult to be applied to non-metal workpieces.